Blender container with off center blade assembly

ABSTRACT

A container ( 15 ) for a blender ( 10 ) includes a bottom surface ( 16 ) having a non-symmetrically shaped perimeter. A side wall ( 17 ) extends upwardly from the perimeter of the bottom surface ( 16 ). A mixing blade assembly ( 20 ) having a plurality of blades ( 21 ) is located above the bottom surface ( 16 ) and is rotatable on an axis which is displaced from the center of the bottom surface ( 10 ). Nonuniform spaces ( 25, 26 ) are thus created between the ends of the blades ( 21 ) and the side wall ( 17 ). The bottom surface ( 16 ) is inclined at an angle relative to the plane normal to the axis of rotation of the blade assembly ( 20 ), and it, as well as the side wall ( 17 ), may be provided with a plurality of spaced vanes ( 31, 32 ).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 10/481,969 filed Dec. 17, 2003, which claims priority fromInternational Application No. PCT/US 02/17827 filed Jun. 5, 2002 nowU.S. Pat. No. 7,063,456 and U.S. Provisional Patent Application No.60/301,081 filed Jun. 26, 2001.

TECHNICAL FIELD

This invention relates to a container used to blend liquids, foods andthe like. More particularly, this invention relates to a blendingcontainer which is especially adapted to more efficiently blend highlyviscous liquids such as encountered in the preparation of frozen drinks.

BACKGROUND ART

Food processors, oftentimes referred to as blenders, are employed to mixor otherwise blend or process a wide variety of foods. In a typicalblender, a container is provided with a blade assembly having aplurality of blades near the bottom thereof which are rotated by a motorsituated in a base or pedestal on which the container is placed. Thebottom of the container is typically formed flat with a regularly-shapedperimeter, for example, a square or a circle, and the blades arerotatable in the center of that regular configuration. As such, a widevariety of ingredients can be blended in these containers including hotliquids, cold liquids, and solids such as ice, fruits and the like.

The blending of most liquids is accomplished by the action of therotating blades whereby the fluid is drawn down through the blades,generally near the center thereof. The fluid then returns to the mainbody of the container by passing upwardly through the gap between thecircumferential tip of the blades and the perimeter of the container.Such is an acceptable flow path when dealing with non-viscous fluids;however, when dealing with viscous fluids, such as are prevalent infrozen drinks, for example, smoothies or the like, flow problems arecreated. Specifically with such fluids, recirculation a significantdistance vertically above the blades is not accomplished and a fluid orice bridge is formed above the blades. As a result, the blades arespinning in a pocket of air and blending is thwarted. When such occurs,the user must usually manually stir the fluid or otherwise break thebridge to force the ingredients down toward the blades. However, withmany viscous fluids, the bridge will again form requiring further userintervention. The blending of viscous fluids without manual interventionthus remains a problem in the food processing art.

DISCLOSURE OF THE INVENTION

It is thus an object of the present invention to provide a container fora blender which assures a more complete blending of the ingredientsbeing mixed.

It is a further object of the present invention to provide a containerfor a blender, as above, which creates an irregular flow pattern todiscourage the formation of an air pocket around the blades in thecontainer of the blender.

It is another object of the present invention to provide a container fora blender, as above, which will effectively mix viscous fluids withoutthe need for manual user intervention.

These and other objects of the present invention, as well as theadvantages thereof over existing prior art forms, which will becomeapparent from the description to follow, are accomplished by theimprovements hereinafter described and claimed.

In general, a container for a blender made in accordance with one aspectof the present invention includes a bottom surface having a side wallextending upwardly therefrom. A rotatable mixing blade assembly ispositioned above the bottom surface, the blade assembly being displacedfrom the center of the bottom surface.

In accordance with another aspect of the present invention, thecontainer includes a bottom surface having a non-symmetrically shapedperimeter. A side wall extends upwardly from the perimeter of the bottomsurface, and a rotatable mixing blade assembly is positioned above thebottom surface.

In accordance with yet another aspect of the present invention, thecontainer includes a bottom surface having a side wall extendingupwardly therefrom. A mixing blade assembly is rotatable on an axis andis positioned above the bottom surface. The bottom surface is inclinedat an angle relative to the plane normal to the axis of rotation of theblender assembly.

Another aspect of the present invention relates to a container for ablender having a blade assembly rotatable on an axis. The container hasa side wall, a side wall surface opposed to the side wall, and asubstantially flat wall on each side of the side walls. Each flat wallintersects the surface, and the surface includes at least one wall whichis substantially flat. The side wall is closer to the axis than theintersections of the flat walls and the surface.

Additionally, the present invention contemplates a container for ablender having a blade assembly rotatable on an axis. The containerincludes a bottom surface and a side wall extending upwardly from thebottom surface. The side wall includes a first surface, a second surfacehaving at least one substantially flat portion, and a pair ofsubstantially flat surfaces, one of the flat surfaces being positionedon each side of the first surface. Each flat surface intersects thesecond surface. The first surface is closer to the axis than theintersections of the flat surfaces and the second surface.

The present invention also contemplates a container for a blender havinga blade assembly rotatable on an axis. The container has a curved sidewall, a side wall surface having two lobes equidistant from the centerof the surface and opposed to the curved side wall, and a substantiallyflat wall on each side of the curved side wall. Each flat wallintersects the surface. The curved side wall is closer to the axis thanthe intersection of the flat walls and the surface.

A preferred exemplary container for a blender incorporating the conceptsof the present invention is shown by way of example in the accompanyingdrawings without attempting to show all the various forms andmodifications in which the invention might be embodied, the inventionbeing measured by the appended claims and not by the details of thespecification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a somewhat schematic side elevational view of a blender havinga container made in accordance with the concepts of the presentinvention.

FIG. 2 is a somewhat schematic, fragmented vertical sectional view ofthe container shown in FIG. 1.

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 2.

FIG. 4 is a sectional view similar to FIG. 3 but showing an alternativeembodiment.

FIG. 5 is a somewhat schematic, fragmented vertical sectional viewsimilar to FIG. 2 but showing an alternative embodiment.

FIG. 6 is a sectional view taken substantially along line 6-6 of FIG. 5.

PREFERRED EMBODIMENT FOR CARRYING OUT THE INVENTION

A blender is shown schematically in FIG. 1 and is indicated generally bythe numeral 10. Blender 10 includes a base portion 11 which, via feet12, may rest on any suitable operating surface. Base 11 houses a motorand other controls which may be operated at a control panel 13. Apedestal 14 is carried by base portion 11 and is adapted to receive thecontainer made in accordance with the present invention and generallyindicated by the numeral 15.

Container 15 includes a bottom surface 16 with a side wall 17 extendingupwardly from the perimeter of the bottom surface 16. Side wall 17 isquite often transparent and generally defines an open top for container15 which can be closed, as desired, by a cover or lid 18. Container 15is most often provided with a handle (not shown) on the side wall, andusually a spout is formed at the top perimeter of the side wall so thatliquid may readily be poured out of container 15.

A blade assembly, generally indicated by the numeral 20, is positionedwithin container 15 above bottom surface 16. Blade assembly 20 can be ofa conventional blender blade configuration and, as such, includes aplurality of radially extending blades 21 which are carried by, andpositioned above bottom surface 16 by, a vertically oriented shaft 22.Shaft 22 extends downwardly through a hub 23 formed in container bottomsurface 16 and is typically connected, as by a spline, to a motor shaft24. As is rather conventional for blenders, placement of container 15 onpedestal 14 automatically makes a connection between blade assembly 20and the motor of the blender such that upon activation of the motor, therotation of motor shaft 24 is transferred to blade shaft 22, and blades21 are rotated above bottom surface 16 of container 15.

The container 15 of the present invention includes several featureswhich enable it to more efficiently blend ingredients which wereheretofore difficult to blend, such as frozen or viscous fluids. One ofthose features relates to the position of the blade assembly 20 incontainer 15. As shown in the drawings, blade assembly 20 is notcentered relative to bottom surface 16. That is, irrespective of theshape of surface 16, be it circular, square, rectangular, or anon-symmetrical shape such as shown in FIGS. 3, 4 and 6, the axis ofrotation of blades 21, as defined by shaft 22, is not positioned on thecentroid of the bottom surface 16.

As a result, a fluid flow pattern, shown by the arrows in FIG. 1, iscreated. This flow pattern is to be contrasted with the flow pattern ofthe prior art wherein the fluid exits the blades at the small areabetween their tips and the side wall of the container and movesuniformly upwardly as a thin sheet along the walls of the container. Thefluid in the prior art is thereafter turned near the top thereof andredirected down toward the center of the rotating blades. It is thisuniform movement, however, which assists in creating the bridge whichforms the air pocket around the blades.

The new nonuniform flow pattern shown in FIG. 1 avoids the problems ofthe prior art. That is, because the clearance between the tips of blades21 and the nearer side wall 17, indicated as 25 in the drawings, isminuscule, as compared to the clearance 26 between the side wall 17further away from blades 21, fluid flow upwardly at clearance 25 isessentially eliminated with the bulk of the upward movement of the fluidbeing directed through clearance 26 in one relatively large concentratedstream. This up-flow therefore occurs only over a portion of thecircumference of blades 21, and uninterrupted down flow through theblades will occur around the remaining portion of the circumference.Such a nonuniform, non-symmetrical or unbalanced flow will disrupt thetendency of the fluid to form the undesirable bridge.

Another factor which contributes to the desired nonuniform flow createdby the present invention is the fact that, in the preferred embodiment,the shape of bottom surface 16 is non-symmetrical or otherwiseirregular. That is, while a desirable flow can be created with anoff-centered blade assembly 20 and a regularly configured or symmetricalbottom surface 16, the desired flow can be enhanced by, and in fact,even independently created by, a bottom surface 16 which is irregular ornon-symmetrical in configuration.

Examples of such non-symmetrical bottom surfaces 16 are shown in FIGS.3, 4 and 6. That shown in FIG. 3 is currently most preferred. Ingeneral, the FIG. 3 configuration is somewhat like a flattened ellipsewith the container side wall 17 having a curved side wall or surface 27on the side nearest to the axis 22 of blade assembly 20 and asubstantially flat surface 28 opposed to side wall 27 on the sidefurther from the axis 22 of blade assembly 20. A generally flat wall orsurface 33 is formed on each side of side wall 27, and walls 33intersect surface 28 at intersections 34. The side wall 27 is closer tothe axis 22 of rotation of blade assembly 20 than the intersections 34.

In the example shown in FIG. 4, the surface 28 is shown as including asmany as four generally flat walls 35, 36, 37, and 38. Walls 35 and 38intersect generally flat walls 33 at intersections 34, and theintersection of walls 35 and 36, and walls 37 and 38 form two lobes 29,rendering the overall configuration generally heart-shaped. As shown,each lobe 29 is generally equidistant from the center of surface 28. Andin FIG. 6, the surface 28 has been rounded, as at 30, to provide anoverall configuration of generally a teardrop shape.

It should be noted that a common feature of all of these configurationsis the side wall 27 on the side of bottom surface 16 adjacent to bladeassembly 20. Side wall 27 is shown as being curved having a radius ofcurvature that generally approximates the curvature of the circle thatthe tips of blades 21 transcribe when rotating. As such, the smallclearance 25 is defined opposite to the direction of greatestdisplacement of blade assembly 20 from the centroid of the bottomsurface 16, and the large clearance 26 is in the direction of thegreatest displacement of blade assembly 20 from that centroid. Thischanging clearance further contributes to the preferred flow because atsmall clearance area 25, flow exiting the blades is unable to squeezeback through the small gap, but rather is swept around under the bladeto escape at area 26 having the larger clearance.

An additional feature which contributes to the nonuniform flow is thefact that in the preferred embodiment, bottom surface 16 is inclined atan angle A relative to the plane normal to the axis of rotation of bladeassembly 20. That is, bottom surface 16 is not horizontal and does notintersect shaft 22 of blade assembly 20 at a right angle. While bottomsurface 16 is shown as a continuous member being oriented at angle Afrom horizontal, it should be evident that it need not be in a singleplane but rather could be made up of a plurality of stepped regionscreating the overall angled surface.

Thus, bottom surface 16 slopes downwardly at angle A from the locationof blade assembly 20 toward the side of container 15 furthest away fromblade assembly 20. That is, bottom surface 16 is the lowest at the areaof the largest blade clearance 26. As such, the sloped bottom generatesa force exiting blades 21 which is the sine of angle A, this force beingparallel to the bottom surface 16 and in the direction away from theaxis of rotation of blades 21 which thereby enhances the flow in thatdirection as previously described. Although the exact extent of angle Ais not critical, it has currently been found that an angle A of aboutten degrees will provide the desired results.

In addition to improving or enhancing the desired flow, as previouslydescribed, the sloped bottom surface 16 provides additional blendingbenefits. By virtue of the sloped bottom surface 16, the distancebetween each blade 21 and the bottom surface 16 will vary as the bladesrotate. As a result, the blades 21 will experience a variation in loadas they rotate, which variation repeats itself with each revolution. Assuch, there is a repeating circumferential hydraulic imbalance whichimproves the pumping action of the blades, which creates additionaldesirable turbulence in the container 15, and which further enhances thenet movement in the direction of the arrow in FIG. 1, as previouslydescribed.

In summary as to the foregoing, at least three factors of the presentinvention enhance the flow in the blending of viscous fluids. Thesefactors are the off-center blade assembly, the non-symmetrical bottomsurface and the sloped bottom surface, which may singly, or incombination, enhance the flow pattern.

In addition to these three features, even further blending optimizationmay be obtained by forming a plurality of adjacent vanes 31 on theportion of side wall 17 furthest away from blade assembly 20. Side wallvanes 31 preferably continue and extend along bottom surface 16 asbottom vanes 32, as shown in FIGS. 5 and 6. These vanes 31 and 32 willreduce the tendency of the created flow from swirling and will focus thedischarge flow from blades 21 into a concentrated stream of upwardlymoving fluid. This stream then provides the majority of the unbalancedforce to discourage the formation of the bridge.

In light of the foregoing, it should thus be evident that a blendercontainer constructed as described herein substantially improves the artand otherwise accomplishes the objects of the present invention.

1. A container for a blender comprising a blade assembly rotatable on anaxis, a curved side wall, a side wall surface opposed to said curvedside wall, and a substantially flat wall on each side of said curvedside wall, each said flat wall intersecting said surface, said surfaceincluding two lobes, said lobes being equidistant from the center ofsaid surface, said curved side wall being closer to said axis than theintersections of said flat walls and said surface.
 2. A container for ablender comprising a blade assembly rotatable on an axis, a curved sidewall, a side wall surface opposed to said curved side wall, and asubstantially flat wall on each side of said curved side wall, each saidflat wall intersecting said surface, said surface including at least onewall which is generally curved and at least one wall which issubstantially flat, said curved side wall being closer to said axis thanthe intersections of said flat walls and said surface.